Karina Turzhanova

Satellite direct-to-cell connectivity can extend 5G Internet of Things (IoT) services into areas without terrestrial coverage by reusing terrestrial mobile-service spectrum. This study examines aggregate interference at a non-terrestrial network (NTN) satellite receiver in selected bands within 694–2690 MHz, where terrestrial duplex arrangements differ between regions. A satellite receiving an uplink may also receive terrestrial downlink emissions from another country using TDD or an overlapping FDD downlink. Six geographical case studies combine satellite motion, population-based terrestrial deployments, and aggregate-interference calculations over a 180 kHz receiver bandwidth. Results are presented as interference-to-noise ratio (I/N) complementary cumulative distribution functions and geographical maps, with nadir and random off-nadir pointing cases. In the evaluated TDD cases, BS contributions dominate the upper part of the aggregate-interference distributions, and elevated interference extends beyond the emitting countries. These findings identify cross-border interference pathways under the assumed deployments, loading, spectral coupling, and antenna patterns. They do not establish that duplex arrangement outweighs deployment density independently of these assumptions. The adopted −6 dB I/N threshold is a screening reference; service availability, link performance, and the effectiveness of mitigation techniques are not evaluated.

The 8.025–8.400 GHz band is one of the key X-band downlink ranges for modern Earth observation satellites, enabling high-rate transmission of imagery and sensor data for agriculture, environmental monitoring, greenhouse gas assessment, disaster response and security-related applications. The potential introduction of 5G networks into this band raises serious concerns about harmful interference to Earth observation ground stations cand, consequently, about the continuity and growth of the global Earth observation data chain. This paper investigates the feasibility of sharing this downlink band between Earth observation systems and 5G networks using a Monte Carlo simulation framework. The model includes a low-Earth-orbit Earth observation satellite with dynamically tracking ground stations and dense urban, suburban and rural deployments of 5G base stations and user devices, together with established radio-propagation and clutter models and representative protection objectives for satellite downlinks. The results suggest that, to keep interference at acceptable levels, ground stations would need to be located far from 5G deployments, which is difficult to achieve in practice and could seriously limit the future expansion of Earth observation infrastructure.

There given to discuss the study results about one of three deployment scenarios performance (in-band deployment mode) of the narrow-band internet of things (NB-IoT) technology. The study is carrying out with help of simulation modeling and experimental testing of the main network parameters, namely: radio coverage, network capacity, user experience, and their dependencies on each other. Comparison of the results of a physical experiment and simulation modeling shows their high convergence and confirms the adequacy of the applied testing methodology. As a case scenario provided an example of NB-IoT implementation on a 4G mobile network in the 800 MHz band, in a suburban area for remote metering applications. The article presents the applying testing methodology of NB-IoT that adapted to the local conditions of radio network planning. Based on the obtained data, adducing the main conclusions about the feasibility of using an in-band scenario for deploying NB-IoT on a 4G network in a suburban environment.